Interleukin-10 (IL-10) genotypes in inflammatory bowel disease

Interleukin-10 (IL-10) is an anti-inflammatory cytokine. Its production in humans is under genetic control, and genotype defines high or low producers of this cytokine. This study addresses the hypothesis that idiopathic inflammatory bowel disease (IBD) patients are more likely to have the low IL-10 producer genotype and phenotype. DNA was extracted from blood cells of patients with Crohn's disease (CD) or with ulcerative colitis (UC) for IL-10 genotyping. The frequency of the high IL-10 producer allele (-1082*G) was decreased in the whole IBD group (41% vs. 51%, P = 0.03) and in the UC patients compared with normal controls (37% vs. 51%; P = 0.04). Hence, there appears to be an association between the IL-10 genotypes and IBD. This suggests that individuals genetically predisposed to produce less IL-10 are at a higher risk of developing IBD, in particular, UC.     

Interleukin-10 (IL-10) polymorphisms are associated with IL-10 production and clinical malaria in young children

The role of interleukin-10 (IL-10) in malaria remains poorly characterized. The aims of this study were to investigate (i) whether genetic variants of the IL-10 gene influence IL-10 production and (ii) whether IL-10 production as well as the genotypes and haplotypes of the IL-10 gene in young children and their mothers are associated with the incidence of clinical malaria in young children. We genotyped three IL-10 single nucleotide polymorphisms in 240 children and their mothers from a longitudinal prospective cohort and assessed the IL-10 production by maternal peripheral blood mononuclear cells (PBMCs) and cord blood mononuclear cells (CBMCs). Clinical episodes of Plasmodium falciparum malaria in the children were documented until the second year of life. The polymorphism IL-10 A-1082G (GCC haplotype of three SNPs in IL-10) in children was associated with IL-10 production levels by CBMC cultured with P. falciparum-infected erythrocytes (P = 0.043), with the G allele linked to low IL-10 production capacity. The G allele in children was also significantly associated with a decreased risk for clinical malaria infection in their second year of life (P = 0.016). Furthermore, IL-10 levels measured in maternal PBMCs cultured with infected erythrocytes were associated with increased risk of malaria infection in young children (P < 0.001). In conclusion, IL-10 polymorphisms and IL-10 production capacity were associated with clinical malaria infections in young children. High IL-10 production capacity inherited from parents may diminish immunological protection against P. falciparum infection, thereby being a risk for increased malaria morbidity.     

Activation antigens on colonic T cells in inflammatory bowel disease: effects of IL-10

Activated T cells that express activation antigens are termed nonprofessional antigen‐presenting cells (T‐APCs). This study evaluates the ability of lamina propria lymphocytes (LPLs) in inflammatory bowel disease (IBD) to become T‐APCs. LPLs were stained by two‐colour immunofluorescence to determine the expression of activation antigens on T cells. Those from actively inflamed IBD mucosa expressed greater amounts of MHC class II (DR) and CD86 than did LPL T cells from disease controls or normal individuals. After culture in IL‐2 with or without IL‐10, the ability of the T‐APCs from IBD colon to stimulate allogeneic peripheral blood T cell proliferation was measured. The T‐APCs from IBD stimulated an allogeneic mixed lymphocyte reaction, particularly through their expression of DR and CD86, as demonstrated by antibody blocking. Normal LPLs acquired these properties only if repeatedly stimulated with allogeneic peripheral blood lymphocytes (PBLs) used as cell lines in the presence of IL‐2. Addition of IL‐10 reduced expression of activation antigens and the stimulatory ability of LPLs from either IBD patients or from these cell lines. In summary, LPLs from active IBD, but not from disease controls, express activation antigens that stimulate naïve T cells, a process that is reduced by IL‐10. This may contribute to perpetuation of the inflammation.     

Contribution of the IL-2 and IL-10 genes to inflammatory bowel disease (IBD) susceptibility

Although the importance of genetic susceptibility to IBD has been established by epidemiological studies, the genes involved remain poorly characterized. Important candidate genes include those encoding the immunoregulatory cytokines IL-2 and IL-10. The aim of this study was to assess the contribution of the IL-2 and IL-10 genes to IBD susceptibility. One hundred and ninety-eight pairs of siblings with IBD were genotyped at dinucleotide repeat polymorphisms within the IL-2 and IL-10 genes, and data analysed by the affected sib-pair method of linkage analysis and the transmission disequilibrium test (TDT). A subset of 89 affected sibling pairs was genotyped at markers flanking the IL-2 gene as part of a genome-wide search. The IL-2 polymorphism showed no linkage to IBD overall, but modest evidence for linkage to the ulcerative colitis (UC) data set (P = 0.028). A microsatellite 4 cM distal to the IL-2 gene showed a similar distortion in the ulcerative colitis subgroup (P = 0.006). The TDT showed some distortion of allelic transmission for the IL-2 polymorphism in the UC group, but this did not reach statistical significance (P = 0.09). Results for the IL-10 polymorphism were not significant. Thus the gene encoding IL-2 may contribute to UC susceptibility, but the effect is modest and must await replication in other data sets. The IL-10 gene does not appear to contribute to the risk of developing UC or Crohn's disease.     

IL-33及其受体ST2在炎症性肠病中免疫调节作用的研究新进展

IL-33是近年来发现的一种IL-1家族的细胞因子,其受体为ST2.IL-33具有双重作用,既能作为分泌性细胞因子,参与调节Th2型免疫应答,诱导前炎性因子的表达,又能作为核因子,定位于细胞核内,起抑制转录作用,阻遏前炎性基因表达.在慢性炎症性肠病(IBD)患者的肠道组织中可查到该细胞因子的表达.研究IL-33及ST2受体有助于进一步了解IBD发病机制,寻找治疗IBD的新靶点.     

Distribution of four polymorphisms in the tumour necrosis factor (TNF) genes in patients with inflammatory bowel disease (IBD)

In 153 patients with IBD, 64 with Crohn's disease (CD), and 89 with ulcerative colitis (UC), as well as in 54 healthy controls (HC), the frequencies of four known di-allelic polymorphisms in the genes for TNF-α and lymphotoxin alpha (LTα) were investigated. In the Dutch population, the alleles of these four polymorphisms are present in only five combinations, called TNF haplotypes: TNF-C, -E, -H, -I, -P. Furthermore, the relation with the presence of perinuclear anti-neutrophil cytoplasmic autoantibodies (P-ANCA) was studied. A small, but statistically significant, association between the polymorphism at position -308 in the promoter region of the TNF-α gene and UC was found. The frequency of the uncommon TNF-α -308 allele 2 was found to be decreased in patients with UC compared with HC (allele frequency of allele 2 in UC patients 0·15 versus 0·25 in HC, P = 0·044). No significant differences in distribution of the TNF haplotypes were found between IBD patients and HC, although there was a tendency towards a higher frequency of the TNF-C haplotype in UC patients compared with controls (haplotype frequency 22% versus 13%; P = 0·19). No statistically significant differences in distribution of the TNF haplotypes were observed between P-ANCA-positive and P-ANCA-negative UC patients. The strength of the associations indicates that TNF genes are not markers for the predisposition to suffer from IBD. They may, however, be markers of subsets of patients with UC and CD.     

TNF,IL-6, and IL-10 cytokines levels and their polymorphisms in renal function and time after transplantation

Immunologic Research - Cytokine polymorphisms can influence their plasma levels and thus affect the immune response in renal transplantation. A total of 146 renal transplant recipients (RTR) were...     

Methylprednisolone differentially regulates IL-10 and tumour necrosis factor (TNF) production during murine endotoxaemia

IL-10 is an endogenous antiinflammatory cytokine that inhibits TNF biosynthesis and protects mice from lipopolysaccharide (LPS)-induced lethality. As synthetic glucocorticoids are widely used as antiinflammatory agents, we analysed the effects of methylprednisolone administration on IL-10 biosynthesis during murine endotoxaemia. We found that low doses of methylprednisolone (2–10 mg/kg) markedly inhibited TNF production but did not affect serum levels of IL-10, while a high methylprednisolone dose (50 mg/kg) increased LPS-induced IL-10 levels. In parallel, we observed that LPS-induced IL-10 production is TNF-independent in this experimental setting. Experiments conducted in vitro indicated that methylprednisolone (from 0·01 to 100 μg/ml) also increased the biosynthesis of IL-10 by LPS-activated mouse peritoneal macrophages. We conclude that methylprednisolone differentially regulates IL-10 and TNF production induced by LPS both in vivo and in vitro at the macrophage level.     

Interleukin-1 beta (IL-1 beta), IL-1 receptor antagonist, and TNF alpha production in whole blood.

The ability of an individual to mount defense responses to infection depend in part on the capacity to produce cytokines such as interleukin 1 (IL-1) and tumor necrosis factor (TNF). The specialized equipment, labor intensity, and sterile practice required for the standard in vitro evaluation of cytokine production can make such evaluation impractical in some clinical situations. We report a method for stimulating whole blood to produce cytokines that can be implemented in laboratories without tissue culture facilities and requires minimal sample preparation. IL-1 beta and TNF alpha production in whole blood samples was stimulated with endotoxin and/or phytohemagglutinin in standard EDTA-containing vacuum collection tubes. After incubation, plasma was removed and frozen for later assay. Comparison of this whole blood method with isolated mononuclear cell cultures indicated a significant correlation for IL-1 beta production (r = 0.746, P = 0.005). This technique also produced the newly described cytokine, IL-1 receptor antagonist. We conclude that the whole blood method is an acceptable alternative to isolated cell culture methods for measuring IL-1 beta in situations that preclude the standard in vitro approach.     

Chlorpromazine specifically inhibits peripheral and brain TNF production, and up-regulates IL-10 production, in mice.

We have previously shown that chlorpromazine (CPZ) inhibits tumour necrosis factor (TNF) production and protects against endotoxic shock in mice. In this paper we investigated the effect of pretreatment with CPZ, 4 mg/kg i.p. 30 min before, compared with dexamethasone (DEX; 3 mg/kg) on the induction of other endotoxin (lipopolysaccharide; LPS)-induced cytokines in the serum of mice, i.e. interleukin-1 alpha (IL-1 alpha), IL-6 and IL-10, and TNF. We also studied the effect of CPZ on serum and spleen-associated TNF. Both DEX and CPZ inhibited TNF production, whereas induction of IL-1 and IL-6 was inhibited by DEX but not by CPZ. DEX did not affect IL-10, while CPZ potentiated its induction. CPZ also inhibited spleen-associated TNF induction in LPS-treated mice, suggesting an effect on the synthesis of TNF. CPZ inhibited TNF induction by Gram-positive bacteria (heat-killed Staphylococcus epidermidis) and by anti-CD3 monoclonal antibodies. Intraperitoneal administration of CPZ also inhibited the induction of brain-associated TNF induced by intra-cerebroventricular injection of LPS. Therefore, CPZ is a more specific inhibitor of TNF production than DEX; in particular, CPZ increased the induction of IL-10, which is a 'protective' cytokine known to inhibit LPS toxicity and TNF production. CPZ inhibited TNF production in vivo, irrespective of the TNF stimulus used to induce TNF. Finally, CPZ did not induce the 'rebound' effect of DEX that, when given 24 hr before LPS, potentiates TNF production, but it did inhibit TNF production after 24 hr.     

Allele frequencies of polymorphisms of TNFA, IL-6, IL-10 and IFNG in an Italian Caucasian population.

Polymorphisms in the regulatory and intronic regions of several cytokines have been associated with differential cytokine production. In this paper we genotyped, using the polymerase chain reaction-sequence-specific primers (PCR-SSP) method, a series of 363 healthy Italian Caucasians with the aim of obtaining a reference population for further studies on the role of cytokines in the inflammatory and immune responses. We also compared the results to those for other populations. The polymorphisms analysed were those of tumour necrosis factor alpha (TNFA), interleukin 6 (IL-6), interleukin 10 (IL-10) and interferon gamma (IFNG). We found that the frequency of allele TNFA*1 at position -380 was 87.7% and that of TNFA*2 was 12.4%, significantly different from those of the UK and Japanese populations but not different from that of a population in Gambia. For IL-10 the frequencies of alleles -1082A and -1082G were 63.0% and 37.0% and those of alleles -819C, - 819T, -592C and -592A were 70.8, 29.2, 70.8 and 29.2%, respectively, significantly different from those observed in south-east England, in Manchester and in an Oriental population from southern China. The frequencies of IL-6 alleles - 174C and -174G were 29.0 and 71.0%, respectively; for IFNG polymorphisms at position -874, in the population under evaluation, the alleles -874T and -874A were present in 44.7 and 55.3% of the subjects, respectively. Genotype frequencies of IL-6 were significantly different from those observed in populations from Germany and from the UK. The analysis carried out by our group indicates that there is heterogeneity in the frequencies of the cytokine polymorphisms among the different Caucasian populations, and this underlines the importance of a 'local' reference population when evaluating the clinical relevance of cytokine gene polymorphisms.     

The combined effect of interleukin (IL)-10 and IL-12 polymorphisms on induced cytokine production

Interleukin (IL)-12 and IL-10 are immunoregulatory cytokines with an antagonistic effect of the T-helper (Th)1/Th2 cytokine balance and provide a functional link between innate and adaptive immune responses. The aim of the study was to investigate the combined effect of -1082A*G in IL10 and +16974A*C in IL12B single nucleotide polymorphisms (SNPs) on induced cytokine production by stimulated peripheral blood mononuclear cells (PBMCs) isolated from healthy donors. The presence of the high-producer IL-12p40 genotype led to diminished production of IL-10 as determined by the -1082*G allele of SNP in IL10. Significantly decreased IL-10 production was detected in AA+AG/GG in comparison with the low-producer IL-12p40 (AC/CC+AG/GG) genotype combination after stimulation with C3bgp (2 +/- 4 vs. 29 +/- 14.2 pg/ml; p = 0.0003) and LPS (33.4 +/- 13.5 vs. 93.3 +/- 59.6 pg/ml; p = 0.019). IL-12p40 production was independent of IL10 genotype. The present results demonstrated that the production of IL-10 from PBMC depended on both -1082A*G in IL10 and +16974A*C in IL12B polymorphisms.     

Colonic explant production of IL-1 and its receptor antagonist is imbalanced in inflammatory bowel disease (IBD)

IBD is associated with an increased activation of intestinal immune cells, which causes overproduction of proinflammatory cytokines such as IL-1β. IL-1β is implicated in mediating the sustained inflammatory response. IL-1 receptor antagonist (IL-1Ra), the naturally occurring inhibitor of IL-1, has been shown to have beneficial effects in experimental models of colitis. In this study we investigated the hypothesis that an imbalance between IL-1 and IL-1Ra exists in IBD by measuring their secretion by explant cultures of colonic biopsies. Freshly homogenized biopsies from involved tissue in IBD patients exhibited significantly lower IL-1Ra/IL-1β ratios than control and uninvolved IBD mucosal tissue. Using explant cultures, in vitro production of IL-1β and IL-1Ra increased progressively during the 4–18-h culture periods. IL-1β secretion was higher in supernatants from involved Crohn's disease (CD) and ulcerative colitis tissue compared with control tissue, and IL-1β levels increased with severity of inflammation. IL-1Ra secretion was not elevated in involved IBD samples, but significantly higher levels were released when moderate to severely involved tissue samples were compared with non-inflammatory controls. Similar to freshly homogenized tissue, explant studies showed that the IL-1Ra/IL-1β ratios were significantly decreased in involved IBD tissue, but not in uninvolved CD or inflammatory control specimens. These data support the hypothesis of an imbalance between IL-1β and IL-1Ra in IBD.     

Interleukin-10 (IL-10) augments allograft arterial disease: paradoxical effects of IL-10 in vivo

Interleukin-10 (IL-10) is an anti-inflammatory helper T cell type 2 (Th2) cytokine that modulates Th1-type cytokine production. Graft arterial disease (GAD) is a vascular obliterative process mediated via the Th1 cytokine interferon-gamma (IFN-gamma); allografts in IFN-gamma-deficient animals do not develop GAD. We investigated the effect of IL-10 and anti-IL-10 on GAD in murine heart transplants and whether anti-IL-10 reestablishes GAD in IFN-gamma-deficient hosts. Major histocompatibility complex class II-mismatched hearts were transplanted for 8 weeks into wild-type or IFN-gamma-deficient mice. In one set of experiments, wild-type hosts received daily administration of phosphate-buffered saline (PBS) or increasing IL-10; in a subsequent set of experiments, wild-type hosts received weekly PBS, rat IgG, or anti-IL-10 monoclonal antibody; IFN-gamma-deficient recipients received weekly PBS or anti-IL-10 monoclonal antibody. Explanted allografts were assessed for parenchymal rejection and GAD, cytokine profiles, and adhesion/costimulatory-molecule expression. Exogenous IL-10 resulted in increased Th2-like cytokine production; nevertheless, it exacerbated parenchymal rejection and GAD and increased CD8(+) infiltration. Anti-IL-10 did not significantly affect the extent of rejection or GAD, cytokine profiles, or immunohistology of the allografts in wild-type hosts. Adhesion molecule (CD54 and CD106) expression was not diminished by IL-10 treatment, and costimulatory-molecule (CD80 and CD86) expression was augmented by administration of exogenous IL-10. Allografts in IFN-gamma-deficient recipients showed mild rejection and no GAD, regardless of anti-IL-10 treatment. IL-10 in vivo thus has markedly different effects than predicted from in vitro experience. Although allografts develop Th2-like cytokine profiles treatment with IL-10 causes exacerbated rejection and GAD.     

Influence of interleukin 1alpha (IL-1alpha), IL-4, and IL-6 polymorphisms on genetic susceptibility to chronic osteomyelitis

The association between cytokine gene polymorphisms and chronic osteomyelitis was investigated in order to determine whether genetic variability in cytokine genes predisposes to osteomyelitis susceptibility. Significant genotypic and allelic associations were observed between interleukin 1α (IL-1α) −889-C/T, IL-4 −1098-G/T and −590-C/T, and IL-6 −174-G/C polymorphisms and osteomyelitis in the Greek population, pointing towards their potential involvement in osteomyelitis pathogenesis.     

Purified native and recombinant human alpha lymphotoxin [tumor necrosis factor (TNF)-beta] induces inflammatory reactions in normal skin

These studies report findings that demonstrate that human alpha lymphotoxin (LT) induces local, visible, and microscopic inflammatory reactions in normal skin. Skin sites in rabbits, when inoculated with a single injection of native or recombinant human alpha lymphotoxin, demonstrated erythema, swelling, and warmth within 5 hr. Erythema peaked between 24 and 48 hr and resolved by 72 hr. Histologic studies of skin sites injected with native LT revealed polymorphonuclear neutrophil (PMN) infiltration and edema beginning as early as 3 hr posttreatment. Individual skin sites that received three daily injections of native LT exhibited persistent erythema and swelling. Palpable induration was evident 24 hr after the second injection in the series. Histologic examination revealed the presence of many PMNs with associated focal dermal destruction, in the form of microabscesses, and scattered mononuclear cells. In contrast, control materials and recombinant human tumor necrosis factor (TNF-alpha) did not induce visible skin reactions in the rabbit. Several additional controls excluded endotoxin as being the agent responsible for the inflammatory skin reactions observed. The ability of LT to induce inflammation may have a role in its antitumor activity and it may be an important endogenous mediator in other immunologic reactions.     

Co-expression of TNF alpha and IL-1 beta in human acute pulmonary fibrotic diseases: an immunohistochemical analysis

To clarify the involvement of TNF alpha and IL-1 beta in the initiation of fibrotic lung diseases, their localization was examined by immunohistochemistry. Fibrotic lung diseases observed were classified into acute and old pulmonary fibrotic changes. The acute fibrotic changes included adult respiratory distress syndrome, acute interstitial pneumonia and idiopathic pulmonary fibrosis with acute exacerbation. Acute pulmonary fibrotic changes histopathologically corresponded to a mixture of the exudative and proliferative phases of diffuse alveolar damage. Both TNF alpha and IL-1 beta were positive in the alveolar macrophages and proliferating type II pneumocytes in acute fibrotic changes. In contrast, positive cells for TNF alpha and IL-1 beta were sparse in the areas of old fibrotic change and in the normal tissue. These findings suggest that TNF alpha and IL-1 beta play an important role in the initiation of pulmonary fibrotic responses and in the architectural remodeling, irrespective of the etiology of fibrotic lung diseases.     

Contrasting effects of IL-4, IL-10 and corticosteroids on RANTES production by human monocytes

RANTES is a chemokine produced in delayed-type hypersensitivity(DTH) and allergic reactions, in which it may contribute tothe recruitment of immune cells. Macrophages participate inthe cellular infiltration in both conditions and they representa potent source of RANTES. To understand the regulation of RANTESproduction by human monocytes, we analyzed the effect of cytokinesand of corticosteroids on this production. We showed that IFN-and tumor necrosis factor (TNF)- cooperated to induce RANTESproduction by monocytes. N-acetylcysteine inhibited this effect,indicating that reactive oxygen intermediates are required forRANTES production. Both IL-10 and corticosteroids antagonizedthe stimulating effect of IFN- and TNF- on RANTES production.In contrast, IL-4 had no effect on IFN--induced RANTES productionand it potentiated the positive effect of TNF- on this production.Thus, the deactivating properties of IL-10 and corticosteroidson macrophage functions include RANTES production, and thismay contribute to the immuno-suppressive effect of both compoundsin DTH and allergic reactions. In contrast, IL-4 has an oppositeeffect on RANTES production and this property may contributeto cell recruitment in allergic reactions. Therefore, althoughIL-10 and IL-4 belong to the T_h2 family of cytokines, they candisplay distinct functions in immune reactions.